Locking Up Hydrochar Toxins Using CaO

[Michael Hayes]

Dear List,

Quicklime has been used for well over 10K years. CaO is not cheap to make, yet it has important uses in biorefineries. Below is a paper that shows simple lime can give hydrochar a structure for the C to form to and many toxins crystallize within the calcium framework.

Taking that into consideration, using CaO, as opposed to lime, can add signicant processing heat, and the method would likely build a more robust calcium framework for the hydrochar. 

Hydrogen can be isolated by such a refinery and directly used in a H2 fuel cell stack. For whatever time a refinery can fuel such cells, the process heat and electrical generation from the H2 cells will run such biorefineries largely for free, beyond the cost of feedstock.

Best regards

Immobilization of heavy metals in contaminated soils by modified hydrochar: Efficiency, risk assessment and potential mechanisms

https://www.sciencedirect.com/science/article/abs/pii/S004896971932861X

Highlights

•

The modified hydrochar was prepared by a facile one-pot lime-assisted hydrothermal method.

•

Modified hydrochar had increased surface functionality, non-crystalline property and pH value.

•

Modified hydrochar showed significantly increased capacity for metal immobilization.

•

Modified hydrochar could be served as a novel cost-effective soil amendment. 

[Greg Rau]

Not clear what the CDR angle is here. Why not just dilutely add CaO to to the surface ocean to do OAE mCDR? ".. using CaO, as opposed to lime", but where I come from, CaO = lime. Please clarify.

Greg

--
You received this message because you are subscribed to the Google Groups "Carbon Dioxide Removal" group.
To unsubscribe from this group and stop receiving emails from it, send an email to CarbonDioxideRem...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/CarbonDioxideRemoval/CABjtO1e4u%3DV7vn_PXGAU%2Bpr17m9TZiYpERaW0HAPLjpueyb2sg%40mail.gmail.com.

[Michael Hayes]

Greg et al.,

Apologies, I meant to say calcium rich plants as a feedstock, as opposed to lime. Calcium rich biomass has been used, yet few are using CaO.

If H2 fuel cells can be supported, and thus excess processing heat is available, producing CaO is possible as an internally provided feedstock, to a large extent. Moreover, a plant-to-biorock production line can be supported. That is a valuable soil additive combination, and the process water is a direct liquid fertilizer.

Selling finely ground biorock, advanced biochar, and liquid fertilizer is all trackable from the marine/land cultivation of biomass to the farmer's gate, and thus should gain a valuable MRV rating. 

The mCDR value comes with the calcium carbonate rich heated disharge of low pCO2 water into surrounding water. A combination of HTL/HTC reactors and a H2 fuel cell stack allows for the CaO to be created as well as also being degraded to calcium carbonate. The exhaust plume of warm end process water speads out due to thermal buoyancy right at the water/air boundary, and it is a microbial feedstock. The MRV ratting can be as simple as tracking the rate of the outfall stream and local water conditions.

Thanks for pointing out the error.

[Michael Hayes]

 A final thought, a continuous stream of hot process water being released out in open water will create cloud streets under most conditions, the colder the air the better. The thermal cooling provided by cloud streets likely overshadows the environmental impact of the hot water being released into the local mid-ocean waters. 

If taken to a significant scale, one could claim an mCDR value as a 'down welling' mCDR method.